Japanese martial arts
Japanese martial arts refers to the enormous variety of martial arts native to Japan.
The historical origin of Japanese martial arts can be found even before the warrior caste of the samurai and the caste system that restricted the use of weapons by members of the non-warrior classes. Originally, samurai were expected to be proficient in many weapons, as well as unarmed combat, and attain the highest possible mastery of combat skills, for the purpose of glorifying either themselves or their liege. Over time, this purpose gave way to a philosophy of achieving spiritual goals by striving to perfect their martial skills.
Ordinarily, the development of combative techniques is intertwined with the tools used to execute those techniques. In a rapidly changing world, those tools are constantly being improved upon, requiring the techniques to use them to be continuously reinvented. The history of Japan is somewhat unique in its relative isolation. Compared with the rest of the world, the Japanese tools of war evolved slowly. Many people believe that this afforded the warrior class the opportunity to study their weapons with greater depth than other cultures. Nevertheless, the teaching and training of these martial arts did evolve, first with conditions on the battlefield (archery giving way to the sword; glaive giving way to spear), then through a long period of peace, and finally into modern times. Over time two trends defined the arts - first there was increasing specialization, and second, many of the arts took on trappings of budo which implies a higher purpose than just the mastering of arms.
The martial arts developed or originating in Japan are extraordinarily diverse, with vast differences in training tools, methods, and philosophy across innumerable schools and styles. That said, Japanese martial arts may generally be divided into koryū and gendai budo based on whether they existed prior to or after the Meiji Restoration, respectively. Since gendai budo and koryū often share the same historical origin, one will find various types of martial arts (such as jujutsu, kenjutsu, or naginatajutsu) on both sides of the divide.